Conductor spacer



March 1965 A. L. MONTEGANI ETAL 3,176,061

CONDUCTOR SPACER Filed NOV. 14, 1961 4 Sheets-Sheet 1 ,5 )3 Z4 INVENTORS,

I: ANTHONY 4. MUN? 64M h! 4 ou/mp March 1965 A. L. MONTEGANI ETAL CONDUCTOR SPACER 4 Sheets-Sheet 2 Filed Nov. 14, I961 March 1965 A1. MONVTEGANI ETAL 3,176,061

CONDUCTOR SPACER Filed Nov. 14, 1961 4 Sheets-Sheet 3 March 30, 1965 Filed Nov. 14, 1961 A. L. MONTEGANI ETAL CONDUCTOR SPACER 4 Sheets-Sheet 4 United States Patent Ofiice 3,176,661 Patented Mar. 30, 1965 7 3,176,061 CGNDUCTOR SPACER Anthony L. Montegani and Heimar Ounapuu, Scarborough, Ontario, Canada, assignors to McGraw- Edison Company, Milwaukee, Wis, a corporation of Delaware Filed Nov. 14, 1961, Ser. No. 152,245 3 Claims. (Cl. 174-40) This invention relates generally to devices for spacing electrical conductors one from the other and more particularly to a spacer which is applicable to high voltage transmission lines.

In the last 30 years the trend toward higher transmission voltages has been self-evident both in this country and thruout the world. Whereas voltages much in excess of 200 kv. were considered high voltages a few years ago, there are today systems in the United States operating at 345 kv. In Europe currently, there are systems operating at nominal 400 kv.

Conservative estimates are that transmission voltages will exceed 500 kv. in the near future and perhaps 600 and 700 kv. in the not too distant future. In any event the upward trend of transmission voltages does not appear to be in any way slackening.

The transmission of electrical energy at high voltages presents a very economical method of transferring power loads over long distances. In this manner generating sites which heretofore have been located too long a distance from load centers are in fact being utilized to generate power today.

However, the utilization of high voltage transmission techniques is not without its problems. Corona discharge which at lower transmission voltages causes radio and television interference, causes at the higher voltages, serious electrical losses which may, particularly on long transmission lines, materially decrease the over-all efiiciency of the system. To eliminate the corona problem in the vicinity of supporting hardware, shielding rings have been provided which contain the hardware within their electric field. By so containing the hardware, the potential difference between the hardware and air is kept below the level at which corona discharges are initiated. Consequently the main limitation involved in utilizing higher transmission voltages has been the corona effect of the conductors themselves.

in the selection of conductors for extra high voltage systems the outside diameter of the conductor is dictated more by the operating voltage than by the conductivity. As the individual conductor diameter decreases the electrical field surrounding the conductor becomes more concentrated. This results in more severe grading of the potential between the surface of the conductor and the air. As the potential difference exceeds the dielectric strength of the air, discharge of the corona type takes place.

Some attempts to reach a compromise, as respect the conductor outside diameter, between electrical grading and conductor conductivity have involved the use of hollow core conductors. By and large these attempts have not been too practical since the cost of these hollow core conductors are prohibitive While their stringing and supporting is exceedingly difficult.

As a result of the shortcomings of hollow core conductors the prevailing tendency has been toward the usage or" bundled conductors. By arranging 2, 3 or 4 small conductors in a uniform configuration the electrical fields of each conductor unite to present a large diameter field to the surrounding air. In this manner tie per unit stress on the air dielectric is reduced while the proper conductivity based on conductor area is maintained.

To maintain the required conductor configuration in this system spacers are utilized at predetermined intervals along the span. The spacers utilized must, for proper performance, have the following inate and operating characteristics:

(1) They must not produce corona at operating voltage (2) They must maintain conductor configuration under wind, ice, etc. loadings (3) They must permit limited movement of the con ductors both in a lateral and longitudinal direction (4)They must have excellent fatigue strength (5) They must be simple to manufacture, install and remove.

We have designed an improved spacer member which we believe overcomes all the inadequacies of prior type spacer members while at the same time incorporating features which heretofore have not been present in this type of spacer.

It is therefore an object of this invention to provide a spacer assembly which will not produce corona at its operating voltage.

It is another object of this invention to provide a spacer assembly which has no portions thereof lying without the V conductor bundle.

Another object of this invention is to provide a simple inexpensive spacer assembly which will maintain the desired conductor configuration under a variety of normal and abnormal conditions tending to alter the configuration.

Another object of this invention is to provide a spacer assembly which will permit limited movement of the condoctors both in a lateral and longitudinal direction but which has a high fatigue strength and which will urge the conductors back to their desired configuration subsequent to their limited movement.

A further object of this invention is to provide a spacer assembly which is corrosion resistant and which is substantially free of audible noise.

Other objects and advantages of our invention will be apparent from the following description of the preferred embodiments of the invention taken in connection with the accompanying drawings in which:

FIG. 1 is a partially cutaway view in elevation of the invention in connection with four bundled conductors;

FIG. 2 is a view of FIG. 1 taken along the lines 2-'-2;

FIG. 3 is a view in elevation of one form of the inven tion in connection with two bundled conductors;

FIG. 4 is a view of FIG. 3 taken along the lines 44;

FIG. 5 is a partially cutaway view in elevation of a slightly modified form of the invention in connection with four bundled conductors;

FIG. 6 is a view of FIG. 5 taken along the lines 6-45;

FIG. 7 is a partially cutaway view in elevation of another slightly modified form of the invention in connection with four bundled conductors; and

FIG. 8 is a view of FIG. 7 taken along the lines 8-8.

Referring now to FIGURE 1, 10 indicates the spacer assembly generally and 11 each of the bundled coriductors. The spacer assembly 10 comprises a plurality of spaced apart conductor and spring gripping portions 12 and a plurality of resilient spring members 13 which serve to join together adjacent portions 12. Each of the portions 12 is preferably identical to every other one of the portions and for purposes of conciseness only one of the portions will hereinafter be described. In particular the portion 12, which may be referred to as a clamp includes a body 14 having two spring receiving projections 15. The projections 15 each have an internal bore 16 which is adapted to receive the end of one adjacent spring member. The spring end when properly seated in the bore 16 is slightly flattened at 17 and flared out at 17' in order to prevent its rotation with respect to the clamp and its disengagement with respect to the clamp.

The end of the body 14 opposite to the projections 15 has a curvate conductor engaging portion .18. A section of the portion 18 has a slot 19 therein which extends into the interior of the body 14-. A C-shaped clam-ping member 20 having a conductor engaging curvate portion 21 and a portion 22 having a screw threaded aperture 23 is received within body 14 by inserting the portion 22 in slot 19. A bolt 24 extends thru a portion of the body 14 and engages the threaded bore 23 of the clamping member 20.

Therefore, when the curvate conductor engaging portion 18 is in contact with one side of a given conductor and the conductor engaging portion 21 is in contact with the other side of the conductor, tightening of the bolt 24 will cause portion 21 to move toward portion 18 thereby fixedly grasping the conductor.

While the clamping assemblies 12 may be made of a wide variety of materials it is somewhat preferred to utilize cast aluminum due to its inherent strength and its resistance to corrosion.

As shown in FIGS. 1 and 2 adjacent clamping structures 12 are joined together by resilient members 13 which have at least one and preferably more coiled portions 13 which materially increase their resiliency and their ability to resist permanent deformation. Each of the coils 13 is in effect generally perpendicular to the bundled conductors 11. The resilient spring members are accordingly made of stainless steel wire for strength, anti-corrosion and anti-fatigue considerations, though certain other materials may be utilized without deviating from the purview of this invention.

The particular structure above described and those subsequently to be described, due to the incorporation of a resilient member connecting the conductor clamps, positively insures the desired conductor spacing while at the same time being flexible enough to allow limited lateral and longitudinal movement of the conductor.

It should also be noted in conjunction with FIGURE 1 that to assemble and disassemble the assembly that only four bolts need be adjusted and that each of the bolts is conveniently accessible. For further convenience and to present a relatively integral structure the last thread on the bolt may be peened over so that all components are kept captive. Also, since once the assembly is affixed to a group of bundled conductors, there are no moving parts, there can be no audible noise.

Referring now to FIGURES 3 and 4 wherein all components are indicated by the reference numerals utilized in FIGURE 1 it can be seen that the basic structure described in connection with FIGURE 1 can be utilized on various numbers and configurations of bundled conductors. The only modification necessary to adapt the basic design to various situations is a slight alteration in the spring size utilized or conversely a slight alteration in the angle between the projecting spring receiving portions 15. As a result the basic design may be utilized without invention to bundle almost any number of conductors in almost any desired pattern.

Referring now to FIGURE there is shown a slightly modified spacer assembly which is indicated generally at 30. As before there are several spaced apart clamping structures 31 that are joined together by resilient members 32 which are coiled at least once intermediate their ends.

The clamping structures 31 are preferably identical to one another and individually comprise mating members 33 and 34 which are similar to one another. Each of the portions 33 and 34 has a projecting spring receiving portion 35 and a conductor gripping portion 36 which is preferably curvate so that it conforms to the conductor. The mating portions 33 and 34 are joined together by nut and bolt assemblies 37. To retain all portions of the clamps captive the last thread on the bolts may be appropriately peened over. As before the spring ends are fiattened at 17 and flared out at 17' so that they will not rotate with respect to or pull out of the associated clamps.

The device of FIGURES 5 and 6 operates in the same manner as those of FIGURES 1 and 2 and has most of the same advantages. It is also somewhat more sturdy in that two bolts are used to hold the conductor per clamp.

Referring now to FIGURES 7 and 8, 49 indicates the spacer assembly generally which comprises spaced apart clamping members 41 which are joined together by resilient members 42. The members 41 include a basal portion 43 which has spring receiving portions 44 integral therewith. The basal portion has cars 45 which have a bore 46 therethru. The upper section of member 43 is provided with a recessed arcuate area 47 which is adapted to engage a conductor 11. A second member 48 has an arcuate portion 49 which is adapted to engage the opposite side of the conductor. A number of ribs 50 are provided on the top of member 48 so as .to define a bolt channel 51. U-bolts 53 are seated in the bolt channels 51 with their legs extending thru the bore 46 in the cars 45. Nuts 52 are fitted on the ends of the bolts 53 so that tightening of the nuts serves to bias the member 48 in a direction toward the basal portion 43 thereby fixedly positioning the conductor 11 therebetween.

The just described assembly has the same advantages described in connection with previous embodiments.

While four particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that various changes and modifications can be made therefrom without departing from the invention and, therefore, it is intended for the appended claims to cover all such changes and modifications as fall Within the true spirit and scope of the invention.

We claim:

1. A conductor spacer for use with a plurality of conductors comprising a plurality of clamps disposed about the periphery of said spacer, each said clamp having a body member with a pair of spaced spring receiving projections and a conductor engaging jaw surface facing radially outward from the axis of said spacer, a movable clamping member having a conductor engaging jaw surface in confronting relation to said body member jaw surface and securing means disposed radially inward of said body member jaw surface intermediate said projections and interconnecting said body member and said clamping member for selectively moving said movable clamping member jaw surfaces toward or away from engagement; and a plurality of spring members equal in number to the plurality of said clamps each formed of a resilient rod having a coiled portion intermediate the ends thereof with the rod end respectively rigidly secured to the spring receiving projections of peripherally adjoining clamp body members.

2. The spacer of claim 1 wherein said movable clamping members each present a conductor embracing portion extending radially outward from said axis beyond the associated one of said conductors retained by said spacer and the remaining spacer components lie radially inward of the conductor retained by said spacer; and further comprising means retaining each movable clamping member and cooperating bolt captive with the associated body member.

3. A conductor spacer for use with a plurality of conductors comprising a plurality of clamps disposed symmetrically about the periphery of the spacer, each said clamp having a body member with a pair of spaced diverging spring receiving projections and a conductor engaging jaw surface facing radially outward from the axis of said spacer, a movable clamping member having a conductor engaging jaw surface in confronting relation to said body member jaw surface, said clamping member and body member cooperating to form a G-shaped clamp opening substantially normal to a line extending radially outward from the axis of the spacer through the clamp, and a bolt interconnecting said body member and clamping member disposed radially inward of said body member jaw surface with the head thereof extending radially inwardly from said body member for selectively moving said clamping member jaw surface toward and away from said body member jaw surface, and a plurality of spring members equal in number to said plurality of clamps with each formed of a resilient rod having a close coiled helical portion intermediate the ends thereof With the axis of said coiled portion substantially parallel to and projecting toward the axis of said spacer, said ends of said rod being respectively rigidly secured within the spring receiving projections of peripherally adjoining clamp body members and said body member jaw surfaces being disposed at a greater radial distance from said axis of said spacer than said spring receiving projections, spring members and bolts.

References Cited by the Examiner UNITED STATES PATENTS 1,589,265 6/26 Stutts et a1 267-26 6 2,149,875 3/39 Talbott 248-63 2,631,873 3/53 Tuck 267-26 X 2,684,825 7/54 Laviana et a1 248-21 X 2,953,624 9/60 Perrone et al 174-146 X 2,974,184 3/61 Mather 174-146 X 3,083,258 3/63 Edwards et al. 174-146 X 3,113,994 12/63 Hammel et al. 174146 X FOREIGN PATENTS 199,721 9/58 Austria.

OTHER REFERENCES Malmstrom: Measure SC Forces on Spacers, Electrical World, vol. 146, No. 26, June 30, 1958, page 45.

Advertisement of Rome Cable Division of Alcoa, Electrical World, vol. 154, No. 5, August 1, 1960, page 52.

JOHN F. BURNS, Primary Examiner. JOHN P. WILDMAN, Examiner. 

1. A CONDUCTOR SPACER FOR USE WITH A PLURALITY OF CONDUCTORS COMPRISING A PLURALITY OF CLAMPS DISPOSED ABOUT THE PERIPHERY OF SAID SPACER, EACH OF SAID CLAMP HAVING A BODY MEMBER WITH A PAIR OF SPACED SPRING RECEIVING PROJECTIONS AND A CONDUCTOR ENGAGING JAW SURFACE FACING RADIALLY OUTWARD FROM THE AXIS OF SAID SPACER, A MOVABLE CLAMPING MEMBER HAVING A CONDUCTOR ENGAGING JAW SURFACE IN CONFRONTING RELATION TO SAID BODY MEMBER JAW SURFACE AND SECURING MEAND DISPOSED RADIALLY INWARD OF SAID BODY MEMBER JAW SURFACE INTERMEDIATE SAID PROJECTIONS AND INTERCONNECTING SAID BODY MEMBER AND SAID CLAMPING MEMBER FOR SELECTIVELY MOVING SAID MOVABLE CLAMPING MEMBER JAW SURFACES TOWARD OR AWAY FROM ENGAGEMENT; AND A PLURALITY OF SPRING MEMBERS EQUAL IN NUMBER TO THE PLURALITY OF SAID CLAMPS EACH FORMED OF A RESILIENT ROD HAVING A COILED PORTION INTERMEDIATE THE ENDS THEREOF WITH THE ROD ENDS RESPECTIVELY RIGIDLY SECURED 